MX2014007181A - Oil-in-water cosmetic compositions. - Google Patents

Abstract

An oil-in-water emulsion cosmetic composition comprising solid particulates of 2-hydroxystearic acid having a particle size distribution such that 99% or more by weight have a particle size of less than 125 microns and a method of manufacture of such a composition.

Description

COSMETIC COMPOSITIONS OF ACEITE-IN-AGU A The present invention relates to oil-in-water emulsion cosmetic compositions and methods for making same. In particular it relates to aqueous antiperspirant compositions suitable for roll-on application and to aqueous cosmetic compositions comprising 12-hydroxystearic acid.

Cosmetic compositions in the form of oil-in-water emulsions have been known for some time. They have found use in many types of cosmetics, notably creams and lotions for the skin. They have also been used as the basis for antiperspirant compositions, in particular those designed for application of a roll-on dispenser.

The roll-on application is achieved by using an I-on roll dispenser, in which a roll, very usually a spherical ball, protrudes partly out of a housing in the mouth of the dispenser that allows the roll to rotate and transport fluid from inside the dispenser by adherence to its surface. Users apply the composition by rotating the roller through the skin surface.

Normally, cosmetic oil-in-water emulsion compositions suitable for roller application are emulsions with relatively small amounts of oil emulsified in an aqueous continuous phase. It is much less common for such compositions to comprise solid components since these can lead to problems in dispensing via the spinning ball and possible difficulties of formulation and / or stability.

Stability difficulties can manifest themselves during storage and / or transport. It will be noted that such storage and / or transportation may need to take place over a wide range of temperatures, from sub-zero to 45 ° C and above in some locations.

Many antiperspirant compositions comprising 12-hydroxystearic acid are described in the prior art because hydroxystearic acid has been widely used as a structurant or thickener in antiperspirant compositions. Although this function may be highly desirable in bar formulations, it may be less desirable in other formulations, such as those intended for roll-on application (vide infra).

WO 98/27954 (P &G) and WO 98/27948 (P &G) describe antiperspirant gels and gel solids optionally comprising 12-hydroxy-stearic acid in an anhydrous carrier fluid.

WO 04/071476 (Unilever) discloses suspension bar formulations optionally comprising 1 2-hydroxy esthearic acid; however, these formulations are again anhydrous. 1-Hydroxystearic acid, among other compounds that are capable of reducing the melanin content of the skin, is known as a skin lightening agent.

WO 09/153169 (Unilever) discloses cosmetic compositions comprising 12-hydroxy-stearic acid, among other agents, and the use of such compositions to lighten the skin. Because the Armpit darkening is a problem that has been observed by users of antiperspirant compositions, the incorporation of 12-hydroxystearic acid in such compositions is a particular objective of the present invention.

The incorporation of 12-hydroxystearic acid specifically in oil-in-water emulsion compositions is challenging due to stability problems. To overcome these problems, the inventors have also found a means to improve the appearance and condition of the skin. In certain embodiments of the invention, anti-transpiration is also delivered.

An object of the present invention is to formulate stable oil-in-water emulsion cosmetic compositions, comprising 12-hydroxy-styic acid, which are suitable for application to the surface of the human body from contact dispensers, in particular roll-on dispensers. .

An objective of certain embodiments of the present invention provides means for delivering both anti-transpiration benefits and appearance of the skin from a single topically applied composition.

According to a first aspect of the invention, there is provided an oil-in-water emulsion cosmetic composition comprising a continuous phase having water as the main constituent and dispersed therein droplets comprising a liquid oil, characterized in that it also comprises independent solid particulates comprising 12-hydroxystearic acid having a particle size distribution, so that 99% by weight or more have a particle size of less than 125 microns.

According to a particular aspect of the invention, there is provided an oil-in-water emulsion antiperspirant composition comprising from 1 to 40% by weight of an antiperspirant active containing aluminum and / or zirconium and a continuous phase having water as the main constituent , also characterized in that it comprises solid particulates comprising 12-hydroxystearic acid, 99% or more by weight of which have a particle size of less than 125 microns.

According to a second aspect of the invention, there is provided a product for treating perspiration comprising an antiperspirant composition according to the particular aspect of the invention referred to in the paragraph just above and a roll-on applicator comprising a reservoir for holding the composition and a rotating ball to apply the composition to the surface of a human body.

According to a third aspect of the invention, there is provided a method for improving the appearance of the skin comprising the topical application of a composition according to the first aspect of the invention.

According to a fourth aspect of the invention, there is provided a process for the manufacture of an oil-in-water emulsion cosmetic composition, said process for the manufacture of an oil-in-water emulsion cosmetic composition comprising the addition of solid particulates of 12-hydroxystearic acid, 99% or more by weight of which have a particle size of less than 125 microns, to a continuous phase having water as the main constituent at a temperature lower than the melting point of said solid particulates, being the temperature maintained below said point for the rest of the process.

The present invention overcomes the problems associated with incorporating 12-hydroxytartaric acid into an oil-in-water emulsion composition, in particular an antiperspirant composition. Such compositions are difficult to formulate in a manner that gives long-term stability, in particular at elevated temperatures, with thickening and separation with the common problems being.

The incorporation of 12-hydroxystearic acid in oil-in-water emulsion compositions presents particular problems due to the hydrophobic nature of this material, giving its affinity for the oil, and its ability to structure or thicken the emulsion, which can lead to problems Catastrophic logics.

Underlying the problems addressed by the present invention is the thermodynamic instability of the emulsions, a problem that is exacerbated by the presence of hydrophobic structuring agents, such as 12-hydroxystearic acid. The difficulty of incorporating 1 2-hydroxystaric acid is particularly severe in compositions comprising a lamellar phase emulsifying system, with the 12-hydroxystárico acid apparently breaking the lamellar phase unless it is incorporated in the correct manner. The problem too It is exacerbated by the presence of high levels of electrolytes, as found in antiperspirant compositions.

The problems of instability referred to above can be a problem both in the manufacture of emulsions and during their storage. The present inventors have found particular stability problems for oil-in-water emulsions comprising 12-hydroxystearic acid when stored at elevated temperatures, as might be encountered during transportation and storage in certain regions of the world.

The Theological benefits of the present invention are of great value with liquid or cream compositions, ie, compositions that are capable of flowing, usually under relatively low pressure, such as that which can be exerted by the human hand without assistance. Such compositions may become unacceptably thick and / or unable to flow on storage unless steps are taken to address possible Theological problems. Compositions that are capable of merely flowing under gravity are particularly suitable for use in accordance with the present invention.

Herein, the amounts and concentrations of ingredients are percentages by weight of the total composition, unless otherwise indicated and the proportions are proportions by weight.

Herein, the terms "oil" and "liquid oil" are used interchangeably and mean organic material insoluble in water, which is liquid at 20 ° C. Any material having a solubility of less than 0.1 g / 100 g at 20 ° C is considered as insol uble.

In the present, references to viscosities should be understood with viscosities measured at 25 ° C using standard methods.

A preferred oil for use in accordance with the present invention is a fragrance oil, sometimes alternatively called a perfume oil. The fragrance oil may comprise a fragrance or simple component most commonly a plurality of fragrance components. Here, fragrance oils impart an odor, preferably a pleasant odor, to the composition. Preferably, the fragrance oil imparts a pleasant odor to the surface of the human body in which the composition is applied.

The amount of fragrance oil in the composition is commonly up to 3%, advantageously it is at least 0.5% and in particular from 0.8% to 25%.

The total amount of oil in the composition is preferably from 0.1 to 20%, more preferably from 0.5 to 10%, and most preferably from 2 to 8% by weight of the total composition. In certain preferred embodiments, particularly those which also comprise an antiperspirant active containing aluminum and / or zirconium, the oil is present at more than 2.5% and less than 16% by weight of the total composition.

In certain embodiments, it is preferred to include an oil, other than a fragrance oil, having a relatively high viscosity, by which is meant less than 250 cS (mm2.s 1). Such oils can improving the sensory properties of the composition in application and can lead to other benefits, such as emolliency. However, they can accentuate the problems of stability of the composition, making the method of incorporation of 12-hydroxystearic acid even more critical.

Suitable oils may be selected from alkyl ether oils having a boiling point above 100 ° C and especially above 150 ° C, including polyalkylene glycol alkyl ethers. Such ethers desirably comprise between 10 and 20 ethylene glycol or propylene glycol units and the alkyl group commonly contains from 4 to 20 carbon atoms. Preferred ether oils include alkyl ethers of polypropylene glycol, such as PPG-14-butyl ether and PPG-15-stearyl ether.

Suitable oils may include one more triglyceride oils. The triglyceride oils commonly comprise the alkyl residues of aliphatic C7 to C2o alcohols, the number of carbon atoms being selected in conjunction with the degree of olefinic unsaturation and / or branching to allow the triglyceride to be liquid at 20 ° C. An example is jojoba oil. In particular it is preferable, in the triglyceride oil, that the alkyl residues be linear Ci8 groups having one, two or three olefinic degrees of unsaturation, two or three being optionally conjugated, many of which are extractable from plants (or their analogs). synthetics), including triglycerides of oleic acid, linoleic acid, conjugated linoleic acids, linolenic acid, petrosellenic acid, ricinoleic acid, linolenelaidic acid, trans-7-octadecenoic acid, parinárico acid, pinolenic acid, punicic acid, petroselénico acid and estearidónico acid.

Suitable oils may include those derived from unsaturated Ci8 acids, including coriander seed oil, impatiens seed oil balsimin, parinarium laurinarium seed oil grease, sapientiana brasilinensis seed oil, dehydrated castor bean oil, borage seed oil, evening primrose oil, aquilegia vulgaris oil, sunflower oil (seed) and safflower oil. Other suitable oils are obtainable from hemp, and corn oil. An oil especially preferred by virtue of its characteristics and availability comprises sunflower oil (seed).

Additional suitable oils, which may also be emollient oils, comprise alkyl or alkyl aryl ester oils having a boiling point above 150 ° C (and a melting point below 20 ° C). Such ester oils include oils containing one or two alkyl groups of 12 to 24 carbon atoms in length, including isopropyl myristate, isopropyl palmitate and myristyl palmitate. Other non-volatile ester oils include alkyl or aryl benzoates, such as Ci2-15 alkyl benzoate, for example, Finsolv TNMR or Finsolv SunTM.

An additional class of suitable oils comprises non-volatile dimethicones, frequently comprising phenyl diphenyl substitution, for example, Dow Corning 200 350cps or Dow Corning 556.

The continuous phase of the emulsion is comprised predominantly of water, that is, water is the main constituent of the continuous phase. The water content in the continuous phase is preferably 60% or greater, more preferably 70% or greater, and most preferably 75% or greater. The water content in the total composition is preferably 50% or greater, more preferably 60% or greater and most preferably 75% or greater.

Other components that may be present in the continuous phase include short chain (C2-C4) alcohols and especially polyols, such as glycerol, ethylene glycol, propylene glycol and polymers thereof, in particular poly (ethylene glycol) and poly (propylene glycol). Poly (ethylene glycol) of average molecular weight 200 to 600 is a preferred component. Such components can be added to the sensory properties of the composition and, when included, are typically present at from 0.5 to 10% of the total composition.

When employed, the antiperspirant active is one that contains aluminum and / or zirconium, as is commonly used in the art for this purpose. Such active ingredients are soluble in water and are normally completely dissolved in the aqueous continuous phase of the composition.

The antiperspirant active is usually selected from astringent salts, including both inorganic salts, salts with organic anions and complexes. The preferred antiperspirant actives are aluminum, zirconium and aluminum-zirconium chlorides, oxychlorides and hydrochloride salts. Particularly preferred antiperspirant actives are polynuclear in nature, meaning that the cations of the salt are associated in groups comprising more than one metal ion.

Aluminum haiohydrates are especially preferred antiperspirant actives and can be defined by the general formula Al2 (OH) xQy.wH20, in which Q represents chlorine, bromine or iodine, x is variable from 2 to 5 and x + y = 6, while that wH20 represents a variable amount of hydration. Aluminum chlorohydrate (ACH) is the most preferred active.

Zirconium salts are usually defined by the general formula ZrO (OH) 2-xQx.wH20 in which Q represents chlorine, bromine or iodine; x is from about 1 to 2; w is from about 1 to 7; and x and w can have both non-integer values. Particular zirconium salts are zirconyl oxyhalides, zirconium hydroxyhalides and combinations thereof.

The antiperspirant actives as used in the invention may be present as mixtures or complexes. Suitable aluminum-zirconium complexes often comprise a compound with a carboxylate group, for example, an amino acid. Examples of suitable amino acids include tryptophan, phenylalanine, valine, methionine, alanine and, most preferably, glycine.

In some embodiments, it is desirable to employ complexes of a combination of aluminum haiohydrates and zirconium chlorohydrates with amino acids such as glycine, which are described in US 3,792,068 Procter and Gamble Co.). Certain of these Al / Zr complexes are commonly called ZAG in the literature. ZAG assets generally contain aluminum, zirconium and chloride with a of Al / Zr in a range from 2 to 10, especially 2 to 6, a ratio of AI / CI from 2: 1 to 0.9 and a variable amount of glycine.

The antiperspirant actives are preferably incorporated in an amount from 0.5 to 60%, in particular from 5 to 30% or 40% and especially from 10% to 30% of the total composition.

The concentration of antiperspirant active in the aqueous continuous phase is preferably from 1% to 40%, more preferably from 5% to 30%, and most preferably from 10% to 20% by weight of the continuous phase.

It is preferred that the emulsifier (s) used in compositions of the present invention form a layered phase emulsifying system in the composition. Such systems can be easily identified by means of optical microscopy. Such systems lead to good emulsion stability, in particular in compositions comprising an antiperspirant active containing aluminum and / or zirconium; however, they are particularly sensitive to the presence of 1 2-hydroxystearic acid, necessitating their addition in the correct form (vide supra).

In certain preferred embodiments, the composition comprises a nonionic emulsifier system. Such an emulsifier system conveniently has an average HLB value in the region of from about 5 to about 12 and in particular from 6 to about 1 0. In the preferred embodiments referred to in the paragraph just above, an especially desired MLB average value is from 6 to 9. Such an average HLB value can be provided by selecting an emulsifier having such a HLB value, or more preferably by employing a combination of at least two emulsifiers, a first HLB emulsifier (minor) having a HLB value at the range from 2 to 6.5, such as in particular, from 4 to 6 and a second HLB emulsifier (major) having a HLB value in the range from about 6.5 to 1 8 and especially from about 12 to about 18. When a combination of emulsifiers is employed, the average HLB value can be calculated as an average weight of the HLB values of the constituent emulsifiers.

Lamellar phase emulsifying systems preferably comprise two nonionic surfactants, optionally selected as suggested in the paragraph just above. In a particular embodiment, a first emulsifier is a fatty alcohol, such as cetyl alcohol and / or stearyl alcohol and a second emulsifier is much more hydrophilic, having an HLB of from about 6.5 to 1 8 and especially from about 12 to about 18.

An especially desirable range of emulsifiers comprises a hydrophilic portion provided by a polyalkylene oxide (polyglycol) and a hydrophobic portion provided by an aliphatic hydrocarbon, preferably containing at least 10 carbons and commonly linear. The hydrophobic and hydrophilic portions can be linked via an ester or ether linkage, possibly via an intermediate polyol, such as glycerol. A preferred range of emulsifiers comprises ethers of polyethylene glycol.

Preferably, the hydrophobic aliphatic substituent contains at least 12 carbons, and is derivable from lauryl, palmityl, cetyl, stearyl and behenyl alcohol, and especially cetyl, stearyl or a mixture of cetyl and stearyl alcohols or the corresponding carboxylic acids.

The polyalkylene oxide is often selected from polyethylene oxide and polypropylene oxide or a copolymer of ethylene oxide and especially comprises a polyethylene oxide. The number of alkylene oxide and especially of ethoxylate units within suitable emulsifiers is often selected within the range of 2 to 1 00. Emulsifiers with an average number of ethoxylate units in the region of 2 can provide a value of HLB lower than 6.5 and those having at least 4 such units provide a higher HLB value above 6.5 and especially those containing at least 10 units of ethoxylate, which provide a HLB value above 10. A combination preferred comprises a mixture of an ethoxylate containing 2 units and one containing from 1 0 to 40 units, such as from 1 to 30 or desirably from 20 to 25. In particular, conveniently, the combination of emulsifiers comprises steareth-2 and a from estearet-15 to estearet-30.

It is desirable to employ a mixture of ethoxylated alcohol emulsifiers in a weight ratio of emulsifier having a H LB value of less than less than 6.5 to emulsifier having a value of HLB greater than more than 8 from 2: 1 to 6: 1 and in particular from 4: 1 to 6: 1.

The total proportion of emulsifiers in the composition is usually at least 1% and in particular at least 2% by weight. Commonly, the emulsifiers are not present above 10%, often not more than 7% by weight and in many preferred embodiments up to 6% by weight. A particularly desirable concentration range for the emulsifiers is from 2.5 to 5% by weight.

Solid particulates comprising 12-hydroxystearic acid preferably comprise a high level of 1 2-hydroxystárico acid, by which is meant at least 50%, more preferably at least 75% and most preferably at least 80% by weight, ignoring any associated surfactant. The other components in the solid particulates are usually alternative solid fatty acids.

It is preferred that the solid particulates comprise only a low level of components which, in isolation, would be liquids at 20 ° C. It is preferred that the total level of such components be less than 10%, more preferably less than 5%, and most preferably less than 2% by weight. This is particularly true when the particulates are dry milled to give them their particle size distribution and especially when they are dry milled and have the preferred particle sizes indicated below.

Solid particulates comprising 1-hydroxy-stearic acid are preferably present at from 0.1 to 10%, more preferably from 0.25% to 8%, and most preferably from 0. 5 to 5% by weight of the total composition. In certain preferred embodiments, in particular those comprising an antiperspirant active containing aluminum and / or zirconium, solid particulates comprising 12-hydroxysthearic acid are present at more than 1% and less than 3% by weight of the total composition.

It is preferable that the solid particulates be ground dry. By this it is meant that the particulates are reduced in particle size by grinding or grinding them in the absence of any additional fluid and at a temperature at which the particulates are solid. This is done before its incorporation into the emulsion composition.

Throughout this description, references to particle size should be understood as the maximum dimension of the particle or particulate, these latter terms being used interchangeably.

The particle size distribution of the solid particulates comprising 12-hydroxystearic acid is preferably so that at least 99% by weight of them have a particle size of less than 125 microns. The average particle size of the particulates (by volume) is preferably less than 75 microns and more preferably less than 50 microns. Particle size distributions can be analyzed using light scattering techniques on instruments, such as the Malvern Mastersizer and / or the Sympatec Helos particle size analyzer.

In certain embodiments, the particulates have a non-ionic surfactant of high relative HLB, by which is meant 1 0 or greater, associated with them. This may enhance the mixing of the solid particulates in the composition and may improve the stability of the formulation, in particular when the particulates comprise the high preferred levels of 1 2-hydroxy estárico acid in the previous paragraph. Normally, the nonionic surfactant is associated with the surfaces of the particulates.

A preferred high HLB nonionic surfactant for use in the above aspect of the invention is an alkoxylated fatty acid of fatty alcohol chain length of C 1 6-C 1 8 and alkoxylation degree of 10 to 30. Estearet is particularly preferred. 20, as available under the name Brij S20 PA, from Croda Europe Ltd.

In certain alternative embodiments, the particulates have a powder flow attendant associated with them. In these embodiments, the particulates tend to be added as a dry powder and the powder flow aid aids in the flow of the powder in the formulation. A preferred flow aid is silica, in particular hydrophobically modified silica, such as silica dimethylsilicate, available as HDK® H30 from Wacker Cheie GmbH. When employed, such flow aids are normally used at from 1 to 30% by weight of the solid particulates.

An optional ingredient that can further improve the emulsion instability is a particulate silica, such as amorphous silica and especially a fumed silica.

Additional optional ingredients include preservatives, dyes and anti-microbials including deodorants conventional Opaqueous agents, such as titanium dioxide, can also be used in some formulations.

Additional particularly preferred ingredients include other skin care active ingredients, especially active for additional skin care that can improve skin lightening.

In certain embodiments, the waxes are preferred additional ingredients. Waxes are hydrophobic, solid organic compounds, usually having a melting point of more than 30 ° C. They can serve to add rheological stability and thicken the composition. Certain waxes can be part of a lamellar phase emulsifying system (vide supra). Preferred waxes are fatty alcohols, in particular those having a chain length of 16 to 18 carbon atoms, and fatty esters, in particular glyceryl esters and especially glyceryl mono-esters of fatty acids having from 16 to 18 carbon atoms .

When the waxes are employed, the total amount is preferably from 1 to 30%, more preferably from 5 to 20, and most preferably from 8 to 15% by weight of the total composition.

The manufacturing process is a key aspect of the present invention. In this process, it is critical that the particulates comprising 1 2-hydroxy-esteric acid are of particle size, controlled, in particular produced, so that 99% or more by weight have a particle size of less than 125 microns. These particulates are added to a continuous phase, having water as the main constituent at a temperature that is lower than the point of melting said solid particulates, in particular at 50 ° C or less and especially at 45 ° C or less.

When the composition also comprises from 1 to 40% by weight of an antiperspirant active containing aluminum and / or zirconium dissolved in the continuous phase, the manufacturing process preferably involves the addition of the particulates comprising 12-idroxystearic acid to an aqueous phase that already has said antiperspirant active dissolved in it. The products of superior Theological properties were obtained using this route.

In a preferred manufacturing process, the solid particulates comprise less than 10%, more preferably less than 5%, and most preferably less than 2% by weight of components which, in isolation, would be liquids at 20 ° C.

In particular, when the solid particulates comprising 12-hydroxy-styic acid have a low content of liquid components, as described in the preceding paragraph, it is preferred that they be ground to give the required or even preferred particle size as described above, before that the particulates are incorporated into the final composition. Preferably this is done by dry milling, that is, in the absence of any liquid.

In certain aspects of the invention, the solid particulates are added as a dispersion in water, preferably with a relatively high non-ionic emulsifier of HLB, by which is meant 10 or greater. This improves the mixing of the solid particulates in the composition and can improve the formulation stability, in particularly when the particulates comprise the preferred high levels of 12-hydroxystárico acid indicated in the previous paragraph. The dispersion preferably has the high HLB nonionic emulsifier present at a level from 1 to 20% by weight of the total weight of the particulates and more preferably at a level of from 2 to 15% by weight thereof.

The concentration of particulates in the aqueous dispersion is preferably from 5 to 60% by weight and more preferably from 10 to 50% by weight.

A non-ionic emulsifier of high H LB preferred for use in the above aspect of the invention is an alkoxylated fatty acid of fatty alcohol chain length of C 6-Ci 8 and degree of alkoxylation from 10 to 30. Steareth is particularly preferred. 20, such as that available under the trade name Brij S20 PA, from Croda Europe Ltd.

In preferred embodiments, the solid particulates are added as a dry powder, preferably with an auxiliary flow, such as silica, the preferred options for which are described above.

In a further embodiment, the process can involve the preparation of gel particulates comprising 1 2-hydroxystearic acid, which are then incorporated into the emulsion. In this process, the 1-hydroxystearic acid is melted; emulsified in water, preferably with a relatively high non-ionic emulsifier of H LB, by which is meant 10 or more; cut enough to reduce the particle size of the droplets comprising the fused 12-hydroxystárico acid; and then cooled rapidly, preferably by direct addition of cold water. The emulsion is usually formed at a temperature of at least 60 ° C and preferably at a temperature of at least 70 ° C. When cold water is added to achieve cooling, this usually has a temperature of 20 ° C or less. A preferred nonionic emulsifier for use in this aspect of the invention is an alkoxylated fatty acid fatty alcohol chain of length of C 16 -C 18 and an alkoxylation degree of from 1 to 30. Estearet 20 is particularly preferred, as is available under the tradename Brij S20 PA, from Croda Europe Ltd. The particle size distribution of the gel particulates needs to be such that 99% or more by weight of them have a particle size of less than 125 microns.

The additional support of the gel particle preparation method described in the preceding paragraph can be found in articles by Kilrov et al in Physicochemical and Engineering Aspects, 328, 1-7, 2008 and J. Phys. Chem. B, 1 1 3, 1 1 101 -1 1 108, 2009.

In a certain preferred aspect of the invention, the dry particulates are added to the sub-surface, that is, at a point under the upper surface of the liquid composition being preferred. This is preferably done by having the composition at a pressure less than atmospheric and opening a sub-surface valve to allow the entry of the particulates. This method is particularly suitable when the particulates are added as a dry powder and especially so when the dry powder is added with a flow aid, such as silica.

The compositions used in the present invention are well suited for dispensing via a roll-on dispenser, for example, any vertical dispenser, such as described in EP1 1 75165 or an inverted dispenser, as described in US651 1 243 or WO05. / 007377. Inverted indicates that the dispenser is held vertically in a stable manner with its dispensing ball below the formulation reservoir.

The formulation of the invention is applied by rotating the ball of the dispenser topically through the skin surface, depositing a film of fluid on the skin. Commonly, the dispenser is cleaned through the skin between 4 and 10 strokes, depending on the habit of the user and the diameter of the ball. Commonly from 0.2 to 0.5 g of fluid is deposited in each armpit per application.

Having given a brief summary of the present invention and preferred embodiments, a more detailed description of certain embodiments will be given by way of example only.

Examples The examples according to the invention are indicated by number and the comparative examples are indicated by letter. All amounts and proportions are by weight and the amounts tabulated are percentages, unless otherwise indicated.

The preparation method of Comparative Example A and Examples 1 and 2 involved the following steps. Water, aluminum chlorohydrate, and glycerol were placed in a vessel equipped with a circulation circuit and heated to 40-45 ° C with agitation via circulation through the circuit and via a mixer in the vessel. Estearet 20 was added and allowed to completely dissolve in the mixture (but approximately one third added with 12-HSA in Example 2, vide infra). In a separate vessel, Estearet 2 was melted in the sunflower oil upon heating to approximately 65 ° C. This oil phase was injected into the aqueous phase (water, aluminum chlorohydrate, glycerol and Estearet 20) via the circulation circuit and the resulting mixture subjected to high-cut mixing (8000 rpm) using an inline dynamic mixer (Ultra- Turrax T50). The mixture was cooled to 40 ° C and the fragrance was added with stirring. Finally, the mixture was subjected to high-cut mixing (8000 rpm) again using the dynamic in-line mixer (Ultra-Turrax T50).

In the preparation of Comparative Example A, the 12-hydroxystearic acid was melted in the oil phase and the resulting oil phase was injected into the aqueous phase as described in the previous paragraph. All other processing steps were as described in the previous paragraph.

Comparative Example A exhibited poor stability when stored at 45 ° C, appearing a separate layer a week.

Table 1 (1) Akosun, eg Karlshams. (2) Brij S2 PA, eg Croda. (3) Brij S20 PA; eg Croda. (4) It was added as a 50% aqueous solution, ACH-50, eg Reheis.

In the preparation of Example 1, the 1-hydroxystearic acid was added as a dry powder just after the addition of fragrance. The 12-hydroxystearic acid had a reduced particle size by dry milling, so that 99% by weight was 125 microns or less and the average particle size (by volume) was 32 microns, measured using a Sympatec Helos particle size analyzer. The mixture was stirred to achieve a homogeneous composition.

Example 1 exhibited reasonable stability when stored at 45 ° C, being stable for one week.

In the preparation of Example 2, 12-hydroxystearic acid was added as a suspension in water, moistened with Stearet 20, just after the addition of fragrance. The 12-hydroxy styrene acid used was the same as for Example 1, having a particle size reduced to less than 125 microns by dry grinding and an average volume distribution of 32 microns. The suspension contained 11.56% 12-hydroxystearic acid; 1.73% Estearet 20 and 86.71% water and was added with stirring to the main composition at a weight ratio of approximately 17:83 to give the total composition indicated.

Example 2 exhibited good stability when stored at 45 ° C, being stable over 4 weeks.

Example 3 The 12-hydroxystearic acid and the sunflower seed oil were heated together at about 80 ° C. The resulting molten oil phase was added to water and Estearet 20 at 80 ° C with stirring. The resulting crude emulsion (3.33% Estearet 20; 1 3.33% sunflower seed oil; 6.67% 12-hydroxystearic acid; and 100% water) was sonicated at 80 ° C at high power using a Soniprobe type 7532B (ex.

Dow Instruments, Ltd.) and then shock-cooled by adding cold water (less than 10 ° C) to a weight ratio of 40:60 to give a suspension of gel particulates having a composition of 2.0% Estearet 20; 8.0% sunflower seed oil; 4.0% 12-hydroxystearic acid; and 86.0% water.

The particle size distribution of the gel particle suspension was analyzed using light scattering techniques in a Malvern Mastersizer and a D value [4, 3] of 0.1 3 microns recorded.

Water, aluminum chlorohydrate and glycerol were placed in a vessel equipped with a circulation circuit and heated to 50-55 ° C with agitation via circulation through the circuit. Steareth 20 was added and allowed to completely dissolve in the mixture. In a side pot, stearet 2 was melted on heating to approximately 65 ° C. The molten steareth 2 was then injected into the aqueous phase and the mixture was subjected to high cut mixing (80000 rpm) using an in-line dynamic mixer (Ultra-Turrax T50). A laminar dispersion resulted, the composition having 30.6% aluminum chlorohydrate; 0.6% Estearet 20; 8.2% glycerol; 4.7% Estearet 2 and 100% water.

The suspension of gel particles, at room temperature, was added to the laminar dispersion, at 40 ° C, with agitation, followed by the fragrance, also with agitation. The weight ratio for this mixing step was 50:49: 1 respectively, giving the final composition indicated in Table 1.

Example 3 exhibited reasonable stability when stored at 45 ° C, being stable for two weeks.

Example 4 12-Hiroxystearic acid was melted on heating to approximately 80 ° C. The resulting melt was added to water and Estearet 20 at 80 ° C with stirring. The resulting crude emulsion (3.33% Estearet 20, 6.67% 12-hydroxystearic acid, and 100% water) was sonicated at 80 ° C at high power using a Soniprobe type 7532BH (eg Dow Instruments, Ltd.) and then cooled by shock when adding cold water (less than 10 ° C) to a weight ratio of 40:60 to give a suspension of gel particulates having a 2.0% Estearet 20 composition; 4.0% 12-hydroxystearic acid; and water at 1 00%.

The particle size distribution of the gel particle suspension was analyzed using light scattering techniques in an alvern Mastersizer and a D value [4.3] of 3.1 microns was recorded.

Water, aluminum chlorohydrate and glycerol were placed in a vessel equipped with a circulation circuit and heated to 50-55 ° C with agitation via circulation through the circuit. Estearet 20 was added and allowed to dissolve completely in the mixture. In a side pot, Estearet 2 was melted in sunflower seed oil when heated to approximately 65 ° C. The hot mixture of Estearet 2 and the sunflower seed oil was then injected into the aqueous phase and the mixture was subjected to high-cut mixing (8000 rpm) using an in-line dynamic mixer (Ultra-Turrax T50). The resulting emulsion had the composition 30.6% aluminum chlorohydrate; 0.6% Estearet 20; 8.2% glycerol; 4.7% Estearet 2; 8.2% sunflower seed oil and water at 1 00%.

The suspension of gel particles, at room temperature, was added to the emulsion composition, at 40 ° C, with stirring, followed by the fragrance, also with agitation. The weight ratio for this mixing step was 50:49: 1 respectively, giving the final composition indicated in Table 1.

Example 4 exhibited reasonable stability when stored at 45 ° C, being stable for two weeks.

Comparative Example B of Table 2 was made in a manner analogous to Comparative Example A. As Comparative Example B, it exhibited poor Theo logical characteristics and was unacceptably thick.

Example 5 of Table 2 was prepared in a manner similar to Example 2, although the late added suspension of 12-hydroxystaric acid in water (4.2% by weight) had no surfactant present. The suspension of 12-hydroxystearic acid also had the niacinamide dissolved therein and added at a temperature of 50 ° C. In this example, the sunflower seed oil was added after the suspension of 12-hydroxystearic acid at a temperature of 40 ° C.

It was found that Example 5 has satisfactory logical Teo properties and was not unacceptably thick.

Table 2 Examples 6 to 10 in Table 3 and Examples 1 to 13 in Table 4 were prepared by the same method as described for Example 2 (addition of slurry of 1 2 -hydroxystearic acid wetted by Estearet 20). Example 14 in Table 4 was prepared by the same method as described for Example 1 (addition of 12-hydroxystearic acid as a powder).

Examples 6 to 8 exhibited good stability when stored at 45 ° C, being stable for 4 weeks. Examples 9 and 14 exhibited excellent stability when stored at 45 ° C, being stable for more than 12 weeks.

Table 3 Table 4

Claims (15)

1. CLAIMS 1 . An oil-in-water emulsion cosmetic composition comprising a continuous phase having water as the main constituent and dispersed therein a liquid oil, characterized in that it also comprises independent solid particulates comprising 12-hydroxy-stearic acid having a particle size distribution, so that 99% or more in weight have a particle size of less than 125 microns. 2. An emulsion cosmetic composition according to claim 1, comprising from 1 to 40% by weight of an antiperspirant active containing aluminum and / or zirconium dissolved in the continuous phase. 3. An emulsion cosmetic composition according to claim 1 or 2, comprising a nonionic emulsifying system having an average weight HLB of from 5 to 1 2. 4. An emulsion cosmetic composition according to any preceding claim, comprising a lamellar phase emulsifying system. 5. An emulsion cosmetic composition according to any preceding claim, comprising a liquid oil, other than a fragrance oil, having a viscosity of less than 250 cS (mm2s-1). 6. An emulsion cosmetic composition according to any preceding claim, comprising acid 12- hydroxystearic dry milled. 7. An emulsion cosmetic composition according to any preceding claim, wherein the solid particulates comprise less than 10% by weight of components which, in isolation, would be liquids at 20 ° C. 8. A product for treating perspiration comprising a composition according to any of claims 2 to 7 and a roll-on applicator comprising a reservoir for holding the composition and a rotating ball for applying the composition to the surface of the human body. 9. A process for the manufacture of an oil-in-water emulsion cosmetic composition, said process comprising the addition of solid particulates of 12-hydroxystearic acid, 99% or more by weight of which have a particle size of less than 1 25 microns, to a continuous phase having water as the main constituent at a temperature lower than the melting point of said solid particulates, the temperature being maintained below said point for the rest of the process. 10. A process according to claim 9, wherein the continuous phase comprises from 1 to 40% by weight of an antiperspirant active containing aluminum and / or zirconium dissolved therein. eleven . A process according to claim 9 or 10, wherein the temperature at which the solid particulates are added is 50 ° C or less. 12. A process according to any of the claims 9 to 11, wherein the solid particulates are added as an aqueous suspension together with a nonionic emulsifier of HLB 10 or greater. 13. A process according to any of claims 9 to 11, wherein the solid particulates are added as a powder in combination with a powder flow aid, such as silica. 14. A process according to any of claims 9 to 13, wherein the solid particulates are added below the surface of the continuous phase. 15. A process according to any of claims 9 to 14, wherein the solid particulates are ground to the required particle size prior to their addition to the continuous phase. SUMMARY An oil-in-water emulsion cosmetic composition comprising solid particulates of 2-hydroxystéaric acid having a particle size distribution, such that 99% or more by weight have a particle size of less than 125 microns and a manufacturing method of such composition.